Undying
Part of speech: adjective
Definition: permanent; never-ending; infinite
Immortal
Part of speech: adjective
Definition: Not susceptible to death or aging, never dying or growing older.
Part of speech: noun
Definition: One that is not susceptible to death.A member of an elite regiment of the Persian army.A member of the Académie française.
Example sentence: Truth is immortal; error is mortal.